Oil question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

76bonanza · 12-29-2004, 10:14 PM

The previous owner ran 20w50 castrol synthblend so I ran it at my last change, but this change I would like to run 10w40 same castrol synthblend.

I dont mind the brand just 20w50 seems so thick.

My question is do you think it might leak worse going to a lighter blend? It leaks a very small amount now not even enuf to drip on the ground I never have to add oil at all between changes which is about 4-5 months 1500-2000 miles I only drive it about 15 miles a day to work.

Thanks for any thoughts.

784X4GUY · 12-29-2004, 10:16 PM

I wouldn't think so try it and see...Later Mike

1972 · 12-30-2004, 05:07 AM

I would use 10w30.

I copy/pasted this info I found:

There're problems with 10W40. Due to the
relatively high level of VII (Viscosity-index improver) chemistry needed
to create a 10W40 non-synthetic oil, 10W40s tend to produce much more
sludge than other grades, and tend to go off-grade faster and more
dramatically than other grades. The recommendation for this oil is one
reason for PRV oiling problems. 10W40 was a popular recommendation during
the PRV years, not just with Volvo but with other manufacturers as well.
You will not find ANY recommendations for 10W40 these days, and not just
because everyone's recommending 5W30.

76bonanza · 12-30-2004, 08:34 AM

I may but the 10w40 I am using is a synthitic blend and I want to go down slowly from 20w50 to 10w30

cliffsta · 12-30-2004, 01:26 PM

there was a good discussion about this months ago, alot of neat stuff was said and linked. If i knew what i was doing i would link over to that old thread.....(cue for someone to do that)
Personally i'd go with 10w30.

kblazer87 · 12-30-2004, 01:53 PM

Quote:

Originally Posted by 76bonanza

I may but the 10w40 I am using is a synthitic blend and I want to go down slowly from 20w50 to 10w30

Hi 76Bonanza,
You don't need to do the change slowly. I use synthetic in all my vehicles and I switch from 5W or 10W30 in the winter to 15W50 for summer driving. I have been doing this for several (about 15) years and have had no ill effects from oil related problems. I tried Dura-Blend once, but didn't care for it. I use Mobil 1 most of the time and have been very happy with it. I would also suggest a premium oil filter as well. Just my .02 worth.
Thanks,
Mike

76bonanza · 12-30-2004, 02:37 PM

Well I already have 4 quarts of the 10w40 so I think I will use it this time and then 10w30 next time. And I mostly use the napa spin flow oil filter. I dont realy want to waste the 4 quarts I have now It should be ok with the 10w40 for a few months I think.

784X4GUY · 12-30-2004, 02:41 PM

I always use Mobil1 5w30 or 10w30 and a Mobil1 filter...Later Mike

76bonanza · 12-30-2004, 02:47 PM

I dont know why the PO used 20w50 does that not seem really thick? Or am I just making to much of it?

12-29-2004, 10:14 PM	#1
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Oil question The previous owner ran 20w50 castrol synthblend so I ran it at my last change, but this change I would like to run 10w40 same castrol synthblend. I dont mind the brand just 20w50 seems so thick. My question is do you think it might leak worse going to a lighter blend? It leaks a very small amount now not even enuf to drip on the ground I never have to add oil at all between changes which is about 4-5 months 1500-2000 miles I only drive it about 15 miles a day to work. Thanks for any thoughts. __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

12-29-2004, 10:16 PM	#2
784X4GUY Did someone say MUD? Join Date: Aug 2003 Location: Pullman,WA Posts: 1,089	I wouldn't think so try it and see...Later Mike __________________ Im in the market guys...so keep ya eyes peeled -------------------- Mini trucks are for guys who cant get it up!

12-30-2004, 05:07 AM	#3
1972 Majician Join Date: Nov 2004 Location: In the Middle Posts: 329	I would use 10w30. I copy/pasted this info I found: There're problems with 10W40. Due to the relatively high level of VII (Viscosity-index improver) chemistry needed to create a 10W40 non-synthetic oil, 10W40s tend to produce much more sludge than other grades, and tend to go off-grade faster and more dramatically than other grades. The recommendation for this oil is one reason for PRV oiling problems. 10W40 was a popular recommendation during the PRV years, not just with Volvo but with other manufacturers as well. You will not find ANY recommendations for 10W40 these days, and not just because everyone's recommending 5W30. Last edited by 1972; 12-30-2004 at 05:15 AM.

12-30-2004, 08:34 AM	#4
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	I may but the 10w40 I am using is a synthitic blend and I want to go down slowly from 20w50 to 10w30 __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

12-30-2004, 01:26 PM	#5
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	there was a good discussion about this months ago, alot of neat stuff was said and linked. If i knew what i was doing i would link over to that old thread.....(cue for someone to do that) Personally i'd go with 10w30. __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

12-30-2004, 02:37 PM	#7
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Well I already have 4 quarts of the 10w40 so I think I will use it this time and then 10w30 next time. And I mostly use the napa spin flow oil filter. I dont realy want to waste the 4 quarts I have now It should be ok with the 10w40 for a few months I think. __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

12-30-2004, 02:41 PM	#8
784X4GUY Did someone say MUD? Join Date: Aug 2003 Location: Pullman,WA Posts: 1,089	I always use Mobil1 5w30 or 10w30 and a Mobil1 filter...Later Mike __________________ Im in the market guys...so keep ya eyes peeled -------------------- Mini trucks are for guys who cant get it up!

12-30-2004, 02:47 PM	#9
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	I dont know why the PO used 20w50 does that not seem really thick? Or am I just making to much of it? __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO



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